Carburetor



R. F. ENSIGN CARBURETOR March 25, 1930.

2 Sheets-Sheet 1 Filed March 6, 1925 Wfl/W March 25A, 1930. R. F. ENSIGN CARBURETOR Filed March e,

1923 2 Sheets-Sheet 2 /III l" llllllll IN VENTOE I Wl TA/Ess:

Patentedv Mar. 25, 1930 UNITED ls'ra'rlas PATENT OFFICE ROY F. ENSIGN, OF SOUTH PASADENA, CALIFORNIA, ASSIGNOR T0 ENSIGN CARBU- RETOR COMANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA CARBURETOB Application filed March 6, 1923. Serial No. 623,251.

This invention includes improvements in carburetors of the character 'set forth in my copending application filed November 25, 1919, Serial No. 340,658; Patent No. 1,658,-

'L 484, dated February 7th, 1928; but I do not Wish to limit myself to carburetors of that particular type as this invention lmay be ap-l plied to carburetors of various types.

An object of this invention is to make im- 1, proved provision for accumulating and delivering accelerating fuel in necessary quantities to the mixing chamber without the aid of mechanically operated devices; and Without interruption of the normal mixture.

Other objects, advantages and features of invention may appear from the accompanying drawings, the subjoined detailed description and the appended claims.

The accompanying drawings illustrate an :o embodiment of means invented by me whereby the foregoing objects are obtained in a down iioW type of carburetor.

Figure 1 is an axial section of a carburetor constructed in accordance with this invention, showing the main fuel passage and the discharge for the accelerating fuel; line w1, Fig. 2 indicates the plane of section. v

Fig. 2 is a fragmental section on line m2, Fig. 1, showing the means for obtaining and Se modifying the depression in the fuel supply chamber; and illustrating the means for lilling in, and discharging the accelerating fuel.

Parts are broken away, and the parts forming the mixture passage and its adjuncts are omitted.

Fig. 3 is an elevation in reduced diameter of thefuel control body with a fragment of the shell in place.

Fig. 4 is a plan of the fuel control body p shown in Fig. 3.

Fig. 5 is a section on line m5, Fig. 3.

Fig. 6 is a section on line m6, Fig. 3.

Fig. 7 is a section on line ,m7, Fig. 3.

In Figs. 5, 6 and 7 the shell is shown in place.

@o rig. e.

Fig. 10 is an enlar ed elevation of the fuel control element, loo ing from the back of Fig. 1, the rightof Fig. 2 and the left of Figs. 3-7. i

Fig. 11 is a developed view of Fig. 3 showing fragments of the shell in place. Arrows indicate fuel and air flow toward the mixing chamber. Parts are broken away to expose interior construction.

Fig. 12 is a section of the development on line m12, Fig. 11, including the shell.

The fuel supply chamber 3 is supplied with fuel through the usual fuel supply connections 6, and the fuel in said chamber 3 is maintained at a 'so-called constant level 7 by the usual float 8 and valve 9.

The fuel is delivered from the fuel supply chamber 3 to the mixing chamber 2 by an automatic depression modifying fuel supply Way for the idling mixture and also for the power mixture. Such fuel supply way leading from the lower part of the constant level fuel supply chamber, comprises a submerged port 10, a riser passage 11, open to an elevated fuel orice or port 12 that is located above the constant liquid level 7 and discharges into the bottom of a suction chamber 16 that is open to a drop pipe bore 13,

directly open to the riser 11 that leads directly up to the elevated fuel port 12 which is above theconstant level 7 of the supply chamber 3, and is directly open to the suction chamber 16 and to the drop pipe bore 13 that leads down to the fuel nozzle 14, which is directly open to the mixing chamber 2 and is subject to the manifold depression controlled by the throttle 15. v

The riser 11 and, elevated port 12 are formed in the control body 35, and are enclosed iny a cylindrical shell 35 that is fitted to such body, the perimeter of which is of circular form.

The cross-sectional area of the elevated port 12 is adjustable by a sleeve 16 that forms the suction chamber 16 and has a portion 17 threaded through the fuelchamber cover 17',

` and that has at its upper end a milled head 18, by which it may be turned to more or less restrict the elevated port 12 from fully open, to fully closed adjustment. The retainer spring 19 holds the sleeve in adjusted position.

rllhe lower end of the drop pipe bore 13 is threaded to receive the upper end of by-pass suction tube d, which upper end of tube d thus forms a bottom to the bore 13 from which the liquid fuel is drawn through the jet outlet 14. Said tube 0l extends down through the bottom of the fitting that forms the mixture passage 5 and is threaded at its lower end to receive the external nut e, which holds the mixture-passage fitting tightly against the vortex chamber 2. The bore 24 of said tube d, with a reduced upward extension tube 25 thereof forms the suction passage extending up through the drop pipe bore 13 and opening into the suction chamber 16at a point above the level of the elevated port 12.

rfhere is also provided an idling by-pass, consisting of a duct 20 shown as extending along underneath the mixture passage 5 and having a suction port 21 beyond the throttle 15, and communicating manifold depression through an annular chamber 22 and a lateral hole 23, to the vertical suction passage 24, 25, to the suction chamber 16. The by-pass duct 20 is also provided with an unregulated vent 26 and with a regulated vent 27 both open to the mixture passage; the vent 27 being controlled by a screw threaded pin valve 28 held in adjusted position by a latch 29 engaging the milled head of the valve.

The adjusting sleeve 16 forming the suc-4 tion chamber 16 is provided with the airbleed 30 which opens from a connecting air chamber 31, that is supplied through the equalizing tube 32, with air from the air inlet 1, so that through the air passage thus formed, air is admitted to the suction chamber 16 under all conditions of carburetor operation.

In the present invention, with the exception of a small predetermined vent, 'the supply chamber 3 is air tight above the fuel level,

there being a gasket34 interposed between the cover 17 and the rim of the supply chamber 3 to which the cover is'tightly clamped.

The delivery of liquid fuel from the constant level supply chamber 3 to the mixing chamber 2 is controlled by the structure including the body 35 and the shell 35 tightly fitted thereon.

For convenience of manufacture, said body is generally cylindrical and is formed with an upper threaded portion 36 onto which the cover 17 is adapted to be screwed, and is provided near its upper end with an upper cylindrical head 37, and toward its lower end with a small cylindrical plug 38 adapted to fit the bore 39 in the bottom of the fuel supply chamber, and is provided below said cylindrical plug 38 with a. threaded portion 40 to receive a clamping nut 41 to draw the cover 17 down tightly onto the gasket 34 on the top of the supply chamber 3, and to clamp the bottom of said supply chamber tightly against the underside of a lower cylindrical head 42 that is just above the plug 38 and is of the same diameter as the upper head 37. The heads 37 and 42 form annular flanges or shoulders. The shell 35 is fitted onto heads 3f and 42, air and liquid tight.

The underside of the shoulder formed by head 42 is so spaced from vthe top of the shoulder formed by head 37 and the top of the threaded portion 36, that the lower head will not contact with the bottom of the sup ply chamber until the cover has been drawn down to compress the gasket 34 to an air tight fit on the supply chamber.

lThe body 35 extends downward below the threaded portion 40 and is centrally cored to form the drop pipe bore 13 from the lower end of which the nozzle 14 extends upwardly aslant to discharge into the vortex mixing chamber 2.

The perimeter of the body 35 is cut away between the cylindrical heads 37 and 42 to form above the head 42 the passages and compartments 11, 47, 452, 48 and 49 between ribs and columnsv 43, 44, 45 and 46. The shell is fittedair and liquid tight on said heads, ribs and columns.

The column 43 extends up from the lower head 42 and terminates below the upper head 37, and is provided with a cut away 'cavity or channel which forms the riser passage 11, that is open at its bottom through the fuel port 10, to the constant level fuel supply chamber 3, and is open at its top through the adjustable elevated fuel port 12 which opens from said passage 11 into the drop pipe bore 13, so that the liquid fuel passing from the constant level fuel chamber 3 through port 10 into riser 11 may, by a depression at the mouth of the fuel through the liquid fuel nozzle. 14 into the mixing chamber.

The rib 46 extends up from the bottom head 42to a level somewhat above constant liquid level 7, and the lower portion of the space around the body 35 not occupied by the column 43 is divided by rib 46 into an accelerating well g and a filling passage 49 which passage is widely open at its top to the well g and is connected to the well by an orifice 50 at a level intermediate the levels of the top of the rib and the bottom of the acceleratin well. Said well lies between the column 43 and the rib 46, in one direction from the column 43, and the filling passage 49 is between the column 43 and the rib 46 in the other direction from said column 43.

The delivery-passage 52 is formed by two ribs 44 and 45 which dip into the accelerating well g and together with the upper head 37 form a bell over a tube 56, the top of which tube is open to the top of the bell 52 above the liquid level 7 and the bottom of which tube is open to the mixing chamber 2. One of the ribs contains a vertical series of normally submerged bleed holes 58.

The accelerating well g is divided into two sections 47 and 48 by the ribs 44 and 45 which terminate somewhat above the lower head 42 so that the accelerating well sections 47 and 48 are connected at the bottom of the well by a passa-ge 53, and act substantially as one .chamber to hold 'a quantity of liquid fuel.

The rib 46 extends a short distance above the constant fuel level 7 and is provided a short distance below such fuel level with the restricted passage 50, which connects the lilling passage `49 with the passage or compartment 48 of the accelerating well, above the level of the top bleed 58.

The accelerating well g is adapted to collect fuel by gravity from the fuel supply chamber.

The accelerating well g is open at its top through the holes 54, to receive air from the chamber 31.

The delivery passage 52 is provided at its top with a small vent 55 open to air chamber 31 to prevent siphoning down the tube 56.

The tube 56 for delivering accelerating fuel to the mixing chamber extends downward through the head 42 from a short distance above the liquid fuel level 7, and opens at its y lower end into the mixing chamber.

The fuel inlet 59 which opens from fuel supply chamber 3 into the filling passage 49, serves to admit fuel to fill the well at low speed and also to allow air to flow from the filling passage into the fuel supply chamber to limit the depression therein at high speeds. Said fuel inlet 59 is submerged below the fuel level 7 and completes the intermittent fuel passage which comprises the inlet 59, filling passage 49, passage 50, chambers 47, 48, connecting passageways 53, and the fuel delivery tube 56.

In order to cause air to flow from the filling passage into the fuel supply chamber, means are provided to apply a depression upon the surface of the fuel in the fuel supply chamber 3. Preferably and as shown, for this'purpose a restricted depression passage is connected from above the fuel level in the fuel supply chamber to a depression zone in the mixing chamber, and comprises a tube 60 open at its upper end to the fuel supply chamber 3 through a free branch 62 and a restricted orifice 63 in the shell 35 and may be open to the chamber 31 by the vent 64.

Means are provided whereby the application of the air depression on the surface of the fuel in the fuel supply chamber may be modiiied. Such means comprise a rotatable plug 65 rotatably mounted air tight in the cover 17 and having a number of different sized ports 66 and a bore 67 communicatingwith said ports and open to the air space in the upper part of the fuel supply chamber.

By turning the plug, any of said ports may be selected and caused to communicate With the atmosphere through the branch 70 and the connecting chamber 31. Said .ports in the present construction correspond in diameter to drill sizes number 55 and 60. A set screw 71 is provided t0 retain the controlling plug 65 in the adjusted position.

When the carburetor is adjusted and ready for operation, the accelerating well will operate as follows When the throttle is closed or nearly closed, fuel will stand in the accelerating well g and the filling passage 49 at approximately the level 7. Upon opening the throttle the increased depression in the mixing chamber will be applied in the passage 52 t rough the tube 56, and fuel will flow up the passage 52 from the accelerating well g and down the tube 56 vto the mixing chamber.

At the same time thefuel is being delivered from the accelerating well to the mixing chamber, suction is applied through the port 61, tube 60, branch 62 and restricted orifice 63, to cause a depression above the fuel in the supply chamber, which depression is reduced and regulated by the air restrictedly admitted from the atmosphere through the vent 64. If the throttle is opened farther and a higher air velocity is attained in the mixing chamber, the depression thus applied to the air above the fuel in the fuel supply chamber becomes sufficient to permit the atmospheric air applied though holes 54, to force fuel from 'the filling passage 49 back through the inlet 59 and into the constant level fuel supply chamber 3, after which air admitted through holes 54 will be drawn by suction caused by 4such higher velocity, through the inlet 59,

whence it will bubble to the surface of the fuel in the supply chamber 3, thus preventing a greater depression above the fuel therein than that imposed by the depth of the inlet 59 belowvthe liquid fuel level in the supply chamber. The passage 49 thus forms a connection to the atmosphere which is'sealed during low air velocities in the mixing chamber, by a column of fuel.

The advantage of using the filling passage 49 as an additional vent lies in the fact that it is closed by the liquid seal during low air velocities in the carburetor. If the vent 66 were made large enough to reduce the depression in the supply chamber at the higher speeds, it would be too large at low speeds. The fuel rises in the filling passage and shuts the passage off' at low speeds.

This arrangement is automatic without movingparts'.

The depression in the float chamber is made sufficiently great to allow air from the atmosphere to flow through the filling passage 49 and fuel inlet 59 by the relative sizes of 63, 64 and 66. 63 is made large enough and 64 and 66 are made small enough to accomplish this result.

After the fuel has been withdrawn from the filling chamber until itis lower than the passage 50, no further fuel will enter the accelerating well until the throttle has been closed to such a point that the depression on the fuel in the vsupply chamber has been diminished so that fuel in the filling passage may rise high enough to fiow through the passage 50.

The location of the passage 50 a short distance below the fuel level 7, insures that ample accelerating fuel will be retained in the accelerating well after the depression has lowered the fuel in the filling. passage, to below the passage 50.

By means of the fixed vent 64 and the rotatable plug 65,'the depression in the fuel supply chamber may be reduced to a degree which will not interfere with the fiow of fuel through 10, ll and 12 to form the normal mixture, and yet will be enough to lower the fuel in filling passage 49 to below the passage 50.

The Vbleed holes 58 serve to reduce the rate of delivery of the accelerating well by allowing air from g to reduce the suction in 52 as said bleed holes are uncovered by lowering of the 'liquid level.

The larger the air bleed into the supply chamber above the fuel, the greaterthe suction required from the mixing chamber to start an appreciable depression in the supply chamber and the higher the suction in the mixing chamber must run before it will bring this depression to the maximum depression which is limited by the submergence of the inlet 59.

I claim 1. In a carburetor having a' fuel supply chamber and a mixing chamber, an acceleratingpwell adapted to accumulate fuel by gravity from said fuel supply chamber, a delivery Y passage to deliver fuel fom said accelerating well to the mixing chamber, a filling passage having an inlet submerged below the level of the fuel in the fuel supply chamber and a passage connecting said filling passage below 1ts normal fuel level with said accelerating well; means to apply a depression upon the surface of the fuel in the fuel supply chamber, and means connecting said accelerating well and filling passage with the atmosphere, whereby the atmospheric pressure forces fuel through said delivery passage from said accelerating well, and into said fuel supply chamber from said filling passage, when depression is applied to the delivery passage and to said supply chamber.

2. In a carburetor having a fuel supply chamber and a mixing chamber, an accelerating well, and an air passage connecting the mixing chamber with the fuel supply chalnber above the fuel; a delivery passage to deliver fuel from said accelerating well to the mixing chamber; a filling passage for the accelerating well having an inlet submerged below the fuel level in the fuel supply chamber; and a passage between said inlet and such fuel level, connecting said filling passage with the accelerating well; and means connecting the accelerating well and filling passage with the atmosphere whereby atmospheric pressure forces fuel through said delivery passage from said accelerating well and into said fuel supply chamber from said filling passage when depression occurs in said mixing chamber.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 27th day of February, 1923.

ROY F. ENSIGN.

ICO 

